This is important to know, because whole investigation is based on scenario with captain locked out of FD.
Because this is what happened. There is recorded conversation between pilots discussing that captain is about to leave the cockpit, captain admitting he should have gone to the bathroom before the flight, FO eager to take over flying duties, there is even a sound of clicks when captain's chair is sliding, click of the door being open/shut, etc. You are way behind the news.